Treatment of artificial materials



Patented June 21, E938 hlllidtl till A dr n-slim MltfiiElldllllLS lHle-nry IDJreyius, London, Enghund No Drawing.

July ii, Serial No, ihllh. in Great July 1 Claim,

This invention relates to improvements in the treatment oi artificial textile materials and is more particularly concerned with theihzation oi titanium or other compounds on artificial slit:

5 materials, and especially to processes for ellect the reduction in the lustre of these materials.

I have found that titanium oxide may vary advantageously bei'ixed in artificial silk by subject ing the artificial sills, impregnated with a titanium to salt, to the action of gaseous ammonia or other volatile lease in conjunction with steam. Preierably the steam is applied before or together with the volatile base. it is most advantageous to apply the ammonia or similar hase simultaneously with the steam, and that a comparatively high temperature, for example a temperature oi the order of to hi5" l1, and more particularly 95 to 105 C. should he employed. ithe materials ob tained by these means are much superior to those obtainable by using ammonia or other mine in solution or in the form of vapour, and without the use of steam. Not only is a better fixation the material of the titanium obtained in the sense that immediately or after an initial scour the precipitated material is much taster tou ashins, but in addition the compound is precipitated in a much hetter form in or on the material. general the precipitate appears to be more iinely divided, giving a better appearance a iabric, for example. llhe invention is not confined to the fixation oi titanium in the artificial materials but may be applied generally to the fixation in or on the materials oi insoluble orrldes. oxides may be in hydrated form. Thus, -.for instance, tungsten, antimony and bismuth may he in the materials in the iorm of their oxides.

the titanium or other metal is preferably ap= plied to the materials in the form of an aqueous solution ofa Water-soluble salt, for example the chloride, sulphate, thiocyanate or other water soluble out of tetra-valent titanium. Very good results may be obtained with comparatively concentrated solutions-e. e. solutions of it to 25% strength. Salts of titanium in other of. oxidation, for example in the tri-valent stage, may be utilized it desired, for instance titanous chloride or thlocyanate may be used. Where tri= talent titanium salts are applied the titanium may subsequently be oidolized at any suitable to stage in the treatment of the materials; For ex:-

ample material impregnated with a titanous salt may be subjected to air or other oxidation before or after the fixation by steam and ammonia or other volatile base.

Any desired methods may be utilized for the (GEL Zit -l) application oi the titanium or other salts to the materials. For example the reagents may he ape plied by hath methods or by padding, spraying, printing or other form of mechanical impregnation. Spraying, printingsnd the hire may be utilized to produce local efiects for the production, for example; of fabrics exhibiting ditlerential lustre. rm methods involving the use of mechanical impregnation are particularly convenient in that they enable the titanium or other to compounds to be applied to the material in predetermined quantities, Padding and spraying are particularly suitable, though predetermined quantities may also be applied by impregnating the material in a bath of the desired reagent and is thereafter hydroextracting or subjectingto suc tion or otherwise treating in order to remove the reagent in excess oi the desired quantity. The material may, for example, he passed through a.

bath of titanium chloride so as to take up excess 2o oi the reagent, and subsequently carried over a perforated drum the interior of which is con-- nected to a suction plant, thereby removing excess titanium chloride. It" desired the material may be subjected to a drying treatment between 25 the impregnation with the titanium or other compound and the fixation of the titanium or other metal by means oi the steam in conjunction with ammonia or other volatile base. Preferably such drying is not carried to completion. The" drying to may, for example, be combined with. a hydroeirtraction, for example, to removeeircess oi the reagent, For instance the perforated drum re to ahove connected'iu turn with the suc-' 'tiou plant may he suitably heated'eo as to eflect 35 a siuiuitaneous and preferably partial drying oil the material.

The invention may he applied generally to artificial sills materials oi all kinds, lit is, however, particularly suitable for reducing the lustre so of artificial sills materials made of or containing cellulose acetate or other organic derivative oil cellulose, for instance cellulose iormate, propionate, butyrate, nltro-acetate or other organicester oi cellulose, or methyl, etluriv or ,beuzyl cellulose 45 or other ether oi cellulose, or mixed ether-esters, for instance oxyethyl cellulose acetate.

' in order to facilitate the wetting or penetration oi the materials by the titanium or similar reagents, wetting agentsor swelling agents for so the materials may he incorporated in the solutions of the reagents, or the materials may be pretreated udth such agents. A .iS. examples of swelling agents for cellulose ester or ether materials may be mentioned alkali or alkaline earth to or other soluble tlriiocyanates. or organic swelling agentsflfor instance acetic acid, formic acid, or other organic acid, ethyl or other alcohol, acetone or other ketone, cyclic ethers, glycol ethers or estersor ether-esters, or aromatic hydroxycompounds. The titanium or other salt may itself be capable of swelling the material under treatment. For instance titanium thiocyanate may be employed in a concentration sufficient to swell the cellulose acetate or other cellulose ester or ether. 7

The materials impregnated as described above with' the titanium or other compound may be treated directly with steam and ammonia or other volatile base. Such an atmosphere may, for example, be obtained by the simple volatilization of a suitable aqueous solution of ammonia or a. volatile base, e. g. methylamine or other volatile aliphatic amine. Preferably, however, the ammonia or other volatile base or a. solution thereof is injected into a steam chamber and is volatilized by the steam. As previously indicated it is advantageous to effect the fixation at a comparatively high temperature. In order to obtain high temperatures the fixation chamber may if desided be maintained under pressure.

The process of the present invention may be carried out continuously, the fabric, yarn or other material being carried continuously through an impregnating bathor padding mangle to the fixing chamber containing steam and ammonia or other volatile organic base, with or without inter-position of any desired intermediate treatment such as hydro-extraction or drying. For instance a cellulose acetate fabric may be padded with a solution of titanium chloride in the cold and carried directly into an atmosphere of steam and ammonia at 100 C. The period of treatment with the steam and ammonia or. other volatile-base may be relatively short. For ex 100 C. the fixation time may be of the order of 2 minutes. 7

After the fixation of the titanium or other metal or element in the materials the latter may be subjected to any suitable scouring operation,

.for example they may be washed in hot water,

for example water at 60 C., and then washed in cold water and finally scoured in a hot dilute soap solution. In general 'a single scour is suflicient to finish the material.

The invention is illustrated but not limited by the following example:-

Example A cellulose acetate fabric is passed through a cold aqueous solution of titanium tetrachloride of 20% strength, the time of passage being about 4 minutes. The material is then squeezed so that it retains about its own weight of the titanium chloride solution, and is thereafter passed through a chamber containing steam at about 100 C., the time of passage being about 2 minutes. Into the steam chamber concentrated aqueous ammonia is injected at such a rate that the fabric issuing from the steam chamber has a substantially neutral reaction. The material is thereafter rinsed in water/and scoured in a hot aqueous soap solution. An excellent matt finish is thus imparted to the fabric.

What I claim and desire to secure by Letters Patent is:-

Process for reducing the luster of cellulose acetate fabric, which comprises passing the fabric through an aqueous solution of titanium tetrachloride of 20% concentration so that said fabric contains about its own weight of the said titanium tetrachloride solution and passing the so treated fabric through an atmosphere of steam and am-, monia at a temperature of about 100 C. for about two minutes.

HENRY DREYFUS. 

